Simon Guggenheim (December 30, 1867 - November 2, 1941) was an American businessman and philanthropist.

The son of Meyer Guggenheim and younger brother of Daniel Guggenheim and Solomon R. Guggenheim, born in Philadelphia, Pennsylvania, Simon Guggenheim settled in Denver and was a Republican senator for Colorado from 1907 to 1913. During his time as a senator, he also served as a chairman of the Committee to Establish a University of the United States.

From 1919 to 1941 he was president of the American Smelting and Refining Company.

He married Olga Hirsh. Following their son's untimely death in 1922 prior to starting college, Simon and Olga Guggenheim established the John Simon Guggenheim Memorial Foundation, which awards grants to scholars and artists. The Guggenheims also donated money to various educational institutions.

Simon Guggenheim died in 1941 and was interred in the Woodlawn Cemetery in The Bronx, New York.